COATING COMPOSITION AND METHOD OF MANUFACTURING PRE-SEALED GALVANNEALED STEEL SHEET FOR AUTOMOBILE WITH USING THE COATING COMPOSITION

摘要

PURPOSE: A coating composition is provided to secure corrosion resistance as two ~ ten times as strong as the corrosion resistance of a conventional steel sheet which is not treated and to extend a corrosion resistant assurance term of an automobile. CONSTITUTION: A coating composition comprises: epoxy resin 10~30 weight%, phenol resin as a hardening agent and isocyanate compound as a secondary hardening agent; tin-based catalyst 0.01~2 weight%; anti-corrosive pigment and conductive pigment 50~80 weight%, polyethylene wax mixture 0.5~2 weight%, and fumed silica or hydroxypropyl cellulose 0.5~1 weight%. A method for manufacturing a pre-sealed galvannealed steel sheet for an automobile comprises the following steps: manufacturing the coating component(120); and coating the galvannealed steel sheet(110) with the coating component.